1. Field of the invention
The present invention pertains to interlacing textile yarns and, more particularly, to a method and apparatus for interlacing the strands of a textile yarn with a fluid current.
2. Discussion of the prior art
Various methods are known in the prior art for producing yarns with interlaced strands, that is, yarns having continuous multifilaments which have been subjected to an interlacing operation to provide the multifilaments with cohesion in place of twisting or twisting and sizing. A "yarn having interlaced strands" or an "interlaced yarn" is formed of continuous multi-filaments, the elementary filaments being interlaced or tangled in a disordered fashion forming "pseudo-knots" in order to produce a yarn having an approximately zero overall twist. Conventional yarn interlacing methods subject the yarn moving under slight tension between two yarn guides in an interlacing zone to the action of a fluid current, normally a jet of compressed air; and, in practice, the jet of compressed air is directed in a plane substantially transverse to the advancing direction of the yarn.
In one prior art method of interlacing yarns, as exemplified by the patent of addition 68,429 to French Pat. No. 1,108,890, the yarn is moved between a nozzle and a resonance box, and in an improvement over the above method, as exemplified by French Pat. No. 1,334,130, the fluid jet is picked up at the outlet of the resonance box to act on the yarn again. In a further prior art method of interlacing yarn, as exemplified by French Pat. No. 1,305,832, the yarn is disposed in a zone of swirling controlled turbulence to have axes of rotation substantially parallel to the advancing direction of the yarn, and one particular manner of implementing this method utilizes a vibrating reed. As exemplified by French Pat. No. 1,492,945, another prior art method of interlacing yarn contemplates simultaneously subjecting the yarn to the action of at least a pair of primary fluid jets and at least one secondary fluid jet acting on the yarn in a direction opposite that of the primary fluid jets and in a zone disposed between the points of impact of the primary fluid jets on the yarn.
All of the above described methods for interlacing yarn known in the prior art include the step of subjecting the yarn to the action of fluid current having a constant or stationary direction and generally a constant output or flow and, while the above described processes are operative to interlace strands of the yarn, such interlacing is not as consistent or as easily obtained as is desirable.